An impairment of traditional radio frequency over glass (RFoG) communication channels is Optical Beat Interference (OBI), thereby afflicting RFoG networks. OBI occurs when two or more reverse path transmitters are powered on, and are very close in wavelength to each other. OBI limits upstream traffic, but can also limit downstream traffic. Existing efforts at mitigating OBI include adjusting ONUs to be wavelength specific, creating an RFoG-aware scheduler in the CMTS, changing ONU wavelengths in real-time, or combining multiple upstream inputs nominally in the same wavelength range.
Optical Beat Interference (OBI) and the limited return link budget are problems in RFoG return networks (see http://www.scte.org/documents/pdf/Standards/ANSI_SCTE_174_2010.pdf for an overview of RFoG networks). In such networks typically a star splitter distributes light over 32 subscribers, the same splitter combines return light from the 32 subscribers at a penalty of 15 dB of loss. Also the optical combining of multiple sources at nominally the same wavelength can cause optical beat interference such that the information content can be overwhelmed by noise.
Thus, improved techniques for reducing distortions in a network are desirable.
It is noted that while the accompanying Figures serve to illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments, the concepts displayed are not necessary to understand the embodiments of the present invention, as the details depicted in the Figures would be readily apparent to those of ordinary skill in the art having the benefit of the description herein.